Sinner, Ruusuvuori, Gaston advance to second round
Sinner needed two hours, 52 minutes to edge past Gregoire Barrere 7-6 (3), 6-7 (5), 7-5. Barrere served for the match at 5-4 in the third set before the Italian found a way to win the final three games.
"I think it was a tough match", he said. "Both of us played at a high level. It was a long match. We were both consistent in every single part of our game and at the end of the day, in the third set, there was a little bit more pressure on both sides.
"He had to serve out the match. After a long match, that isn't easy, and I was [also] a break up. In the end i'm very happy about my first-round match and excited to play one more match."
Sinner next faces Hugo Gaston, who broke Dennis Novak five times in a 3-6, 6-4, 6-1 victory. The Frenchman, granted a wild card into the event, needed two hours to win his first tour-level match since his memorable run to the fourth round of Roland Garros last year.
Nishioka was forced to retire in his match against Emil Ruusuvuori with the Finn leading 6-2, 4-2. Ruusuvuori next faces Matthew Ebden or Benjamin Bonzi.
Doubles gets underway with fourth seeds ousted
Fourth seeds Igor Zelenay and Divij Sharan were upset by the Spanish team of Alejandro Davidovich Fokina and Marc Lopez 6-4, 6-2 while Sander Arends and David Pel knocked out Jo-Wilfried Tsonga and Albano Olivetti 6-4, 6-4.